title: Ultrastructural studies of the peripheral extensions (dendrites) of type I ganglion cells in the cat.
abstract: An ultrastructural study of peripheral extensions (dendrites) of type I ganglion cells in seven healthy adult cats and one cat that underwent bilateral cochlear injection of neomycin was undertaken. Morphologic evidence revealed that the peripheral process (dendrite) consistently has a smaller diameter than the central process. As the dendrite reaches the cell body, there is a constricted segment with a length that ranges from 10 to 30 microns, and a diameter of 0.5 microns. This region is covered by a continuous myelin sheath that does not thin. The central process (axon) does not have a corresponding constriction, and consists of a myelin covered, smoothly tapered segment that extends to the first axonal node of Ranvier. In the deafened cat, some cell bodies of the surviving ganglion cells appeared to have a residual portion of dendrite. These morphologic characteristics might have physiologic implications both in the mechanisms of normal hearing and in cochlear implantation.
authors.affiliation: Minnesota Ear Head and Neck Clinic, Minneapolis.
authors.forename: M V
authors.initials: MV
authors.lastname: Goycoolea
authors.forename: P
authors.initials: P
authors.lastname: Stypulkowski
authors.forename: D C
authors.initials: DC
authors.lastname: Muchow
mesh_terms: D000818:Animals; D001369:Axons / Q000648:ultrastructure; D002415:Cats; D003051:Cochlea / Q000648:ultrastructure*; D003712:Dendrites / Q000187:drug effects / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D009355:Neomycin / Q000633:toxicity; D013136:Spiral Ganglion / Q000187:drug effects / Q000648:ultrastructure*
chemical_list: D009355:Neomycin